


The Armored Heart

by elijahking (orphan_account)



Series: Merciless [4]
Category: Undertale (Video Game)
Genre: Angst, Death, Determination, hoo boy
Language: English
Status: Completed
Published: 2015-10-18
Updated: 2015-10-20
Packaged: 2018-04-26 16:50:13
Rating: Teen And Up Audiences
Warnings: Graphic Depictions Of Violence, Major Character Death
Chapters: 3
Words: 2,623
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5012365
Author URL: https://archiveofourown.org/users/orphan_account/pseuds/elijahking
Summary: <blockquote class="userstuff">
              <p>Farewell.</p>
            </blockquote>





	1. Bare Bones

**Author's Note:**

> this was originally gonna be about flowey but i think i'll save that for another time. also, v short chapter because i'm stupid tired and spent my day stabbing a pumpkin.

A cold, moist breeze inched its way into Undyne's armor. Her fists clenched, resisting the urge to shiver. 

"Papyrus... where are you?"

He was never late. Say what you want about Papyrus, but he was really just a big softie and cared about his job, and he would never miss a meeting. Something about this was off. Very off. She sighed, feeling morose. She really hoped that nothing bad happened to him. Just as she was about to leave, she heard a shuffling from the ledge below the cliff. She spun and crept to the edge, summoning a spear. Squinting, she scanned the patch of tall grass for any movement. After a minute of nothing, she chalked it up to her imagination and slid back into the darkness. 

She was going to go investigate. Papyrus better have a damn good excuse for missing the meeting. Undyne could understand late by maybe five minutes; sometimes he got caught up in practicing or challenging random residents of Snowdin to duels. But over an hour late... it bit down into her nerves like the icy winds.

She started feeling the unease become pure disturbance. It was eerily quiet as she walked the path to Snowdin. Usually, she could hear the screams of children laughing as they lobbed snowballs back and forth or the bell tower sounding off. "Jeez, just what happened... here..."

She stopped in her tracks, seeing only one familiar sight: Sans. He was sweeping what looked like dust into his arms, extremely distraught. Undyne tried calling out to him, but her throat closed up. For the first time in years, she could feel herself beginning to cry. Papyrus had...

He had called her...

Sounding confused and upset...

"I DON'T GET IT. WHAT KIND OF A PERSON DOESN'T LIKE PUZZLES?"

"Well, me, for one."

"OKAY, BUT YOU LIKE JAPES!"

"I do. What's your point, bonehead?"

"WELL... THEY JUST RUB ME THE WRONG WAY!"

"You're not trying to make friends with this human, are you?"

"...NO."

"I can tell when you're lying."

"OKAY, YES. BUT I TRY TO MAKE FRIENDS WITH EVERYONE!"

"Capture them first, and _then_ you can be their friend."

"SOUNDS LIKE A GOOD PLAN! YOU'RE SO GOOD AT THESE THINGS, UNDYNE. OH, HERE THEY COME NOW. SEE YOU LATER!"

...It's what friends were for, right? Papyrus didn't have a bad bone in his body. Neither did any of the monsters she'd ever known. She trembled, crying out in anguish. She _knew_ humans were downright awful, horrific little plagues! 

Every plague has a cure, though. And the thought of eradicating it filled her with determination.


	2. Crossing the Bridge

**Summary for the Chapter:**

> In pursuit of the villain.

**Notes for the Chapter:**

> 'nother short chapter. writing 2k+ words a day takes a lot outta somebody...

Undyne knew Waterfall like no place else. It's where'd she'd grown, trained, battled. And it'd be where she'd die, too, if that was what had to happen. She'd be taking every opportunity she could to, at the very least, scare the shit out of the devil. 

And her first opportunity came. The human seemed to have no interest in reading about the history of the monsters, only destroying them. They passed right by the writings on the wall, eyes filled with a sick determination. They took the small raft from one side of the river to the other, reaching the docks of the Waterfall Swamp. Undyne grinned. Yeah. Walk right into my trap, you little rat. She readied a spear, and as they took their next step, it flew through the air with a whistle. It hit the dock, knocking them backwards. They scrambled up to their feet immediately, sliding around the spear, and took off running. More, more! She summoned three, four, five spears at a time. Always just barely missing them. Their grace between dodging and running was impressive, but not impressive enough. 

Undyne lept over the few feet of water, chasing after them. She swore under her breath. _Why! Won't! You! DIE!!_ She continued to lob spears at them, until they disappeared into a thicket of grass. 

"Ahah! I have you now you..." She stepped in. Clunk, clunk, clunk. Through the thin slit of her helmet, she saw a short silhouette hidden in the darkness. She reached her hand out, grabbed it, and out she pulled...

A... monster. A grinning, wide-eyed, yellow monster kid. His grin widened and a little "hhhhhhhh" of excitement seeped out of his mouth. Undyne blinked a few times, lowered the child, turned, and simply walked the fuck away. She hit herself on the head, berating herself for making such a stupid mistake. The human would have OBVIOUSLY been able to escape. And that monster kid? Sheesh... she hoped to catch up to him in the hopes to tell him to stay the hell away. 

*

Bits of broken bridge crumbled down behind her. Yes, run, run! You can't escape! She threw another dozen or so spears up into the bridge, aiming every spot she could to stop them. The human was injured, stumbling back and forth, having various bits of them slashed at by the unavoidable weapons. Undyne could almost _taste_ the blood on her lips, and it fueled her determination. Only a few more hundred feet. You'll have nowhere to go, human. In the name of Asgore, I will cut you down! 

They were cornered, huffing and wheezing. There was no way they'd be able to go anywhere now. This was it. The end of the line. Undyne grinned, launching herself to the upper bridge. The human turned, limping their way back. 

"'nother way... 's gotta be... another way.."

"Not the way you're going, filth." They lifted their head to look up and down the intimidatingly large warrior. She grinned.

"...you don't scare me."

Undyne barked a laugh and said nothing else. The human tried to stand, but she'd already sent down a barrage of spears, cutting the bridge off right there. She peered over the ledge, her mouth curling into a cynical smile. She watched as they fell, down, down into the abyss. Their figure disappeared into the darkness, and it took a solid minute for the sound of splashing water to reach her ears. Undyne lifted the mouthpiece of her helmet and spit over the edge. 

Good riddance.

*

Undyne rubbed her eyes. She couldn't believe what she saw. _They survived. Holy shit. They survived, and they look... stronger than ever._ Was that even possible? She raked her mind for the possibilities. What are humans even made of?! Something stronger than magic, obviously. Probably hatred and stale cookies. But whatever, they were just... way. Way too close. To Hotland. She couldn't allow this. She WOULDN'T allow this. 

She stepped out of the darkening lantern room. In the distance, the very faint glow of an echo flower illuminated the very dark shape of the human. They were listening to it... how odd, considering... none of the flowers were talking anymore. She stepped closer, readying her most menacing voice. She could hear the very faint whisper of the echo flower...

**B e h i n d y o u .**

The small cave lit up, and the human turned to meet her.

"Seven. Seven human souls. With the power of seven human souls, our king... King Asgore Dreemurr... will become a god. With that power, Asgore can finally shatter the barrier. He will finally take the surface back from humanity..." Undyne could feel her fist clenching hard. "And give them back the suffering and pain we have endured... Understand, human? This is your only chance at redemption. Give up your soul... or I'll tear it from your body." She leaned forward, having no intention of even giving them a chance to give themselves up. They scoffed, raising a hand.

"You don't scare me." They waved their fingers inwards. A challenge.

She summoned her spear and went charging.


	3. Determination

**Summary for the Chapter:**

> Well you may throw your rock and hide your hand  
> Workin' in the dark against your fellow man  
> But as sure as God made black and white  
> What's done in the dark will be brought to the light
> 
> You can run on for a long time  
> Run on for a long time  
> Run on for a long time  
> Sooner or later God'll cut you down

**Notes for the Chapter:**

> Johnny Cash seems oddly appropriate for this fight. I took some liberties with how the fight ends, since you can't actually do what happens in game.

Undyne charged forward, spear in hand. She stopped in her tracks when a flash of yellow flew out in front of her.

"Undyne!! I'll help you!!" The... monster kid from earlier. His grin was so big that Undyne wouldda thought it'd've torn his face apart. He turned to the human, speaking to it as if it was his friend. "Yo!! You did it!! Undyne is RIGHT in front of you!!! You've got front row seats to her fight!!" His smile faltered a bit, looking between the two of them. The human gave Undyne a look that said "can you believe this guy?" Even she shrugged.The realization hit him. "...Wait. Who is she fighting???"

Undyne pinched his cheek between her fingers, scowling. "H-Hey!" He cried out in protest as she started to drag him away. "You're not gonna tell my parents about this, are you?"

When they were out of earshot of the human, she relinquished her grip. "Ow..."

"Listen, kid. You.. you need to stay away from that human."

"Human? WOAH, THAT'S A HUMAN! THAT'S WICKED COOL, YO! I CAN'T BELIE-"

"Zip it, short stuff!" She interrupted him. "It is NOT cool. They've hurt a lot of people. Very, very badly. You need to stay away and let me handle it from here."

"Aww..." He kicked at the ground. Undyne straightened herself out and sighed. She turned back to the direction she needed to go. She was going to end this for good.

*

The human started crossing the frail old bridge. A voice rang out just as they were across. "Yo!!" They groaned. Would this kid ever leave them alone?! They spun around and saw the monster kid running up to them. 

"Yo!" As he walked, he peered over the edge, looking like he was sweating a little. "Yo. Undyne told me to stay away from you. She said you… you hurt a lot of people. …But, yo, that’s not true, right?!" They looked away, staring into the abyss. How annoying. "…yo… why won’t you answer me?" They turned back, a glint of an idea in their head. The smirk on their face was truly malicious. "A… A…and what’s with that weird expression…? Oh… oh man…" The kid turned around, panting, mumbling to himself, "man my h-hearts pounding right out of my chest… what would Undyne do?" He took a deep breath, and turned back to face them. "Yo… y-you’d b-better st-stop r-right where you are… ‘cause if you w-wanna hurt anyone else… you’re… you’re gonna have to get through me, first. A… a…. and…"

They rolled their eyes. "In my way," they snarled. The monster kid looked taken aback, but he braced himself for impact. The human swung its legs into the air, and hit... Armor. Really weak armor. 

"What the hell?" They stepped back. Undyne had flashed down from above, taking the impact. Oh, god, did it _hurt_. She took a heavy breath.

"Undyne… you’re… you’re hurt…" She saw the monster kid there. How the hell he got there was beyond her, but... all that mattered was that he was safe. She gave a proud smirk. 

"Hurt? It’s nothing. Next time, listen when I tell you to leave, okay?" She bent down and gave him a little pat on the shoulder.

"Undyne… I…" Tears welled in his eyes.

"I’ll take care of this! Get out of here!" The kid stumbled away, looking back once sorrowfully. Undyne turned her attention back to the human, who looked, needless to say, unsatisfied. She was about to say something witty, but felt her body collapsing beneath her. "Heh… “it’s nothing”… no… s-somehow, with just one hit… I’m already… already…" She fell to one knee, tremors shaking her entirety. "D… damn it… Papyrus… Alphys… Asgore… just like that, I… I’ve failed you."

Her body started fading, falling apart. Bits of her dust started floating away. But... "No… my body… it feels like it’s splitting apart. Like any instant, I’ll scatter into a million pieces. but… deep, deep in my soul. There’s a burning feeling I can’t describe." She shakily stood back to her feet, garnering a look of hatred from the human. "A burning feeling that won’t let me die. This isn’t just about monsters anymore, is it? If you get past me, you’ll… you’ll destroy them all, won’t you? Monsters… humans… everyone…"

The human smirked, shrugging, like saying, oops! You figured me out! She snarled. "Everyone’s hopes. Everyone’s dreams. Vanquished in an instant. But I won’t let you do that. Right now, everyone in the world… I can feel their hearts beating as one. And we all have one goal. To defeat YOU." She pointed a finger to them. "Human. No, whatever you are. For the sake of the whole world… I, Undyne, will strike you down!" Her body was fading, and fast. But she wouldn't let that happen. In a single moment of focus and determination, she pulled herself together, feeling stronger than ever. She grinned. "You’re gonna have to try a little harder than THAT."

"Hm, cute," they giggled. Damn, that kid was creepy.

They threw out a few kicks, the pearl-pink ballet slippers slapping hard against her armor. Barely a dent! She chuckled, tossing a few bullets out.

“That’s it?” They grinned, dodging them. “Easy.” And then they were knocked to the side by the faster ones, having not expected that. Undyne though she heard them swear. Where do kids learn this stuff, honestly? She shot out more, right as they pulled out what looked to be a stick to deflect the bullets. They were a tad too slow, being pushed around, gashes and stab wounds bleeding freely. Determined as ever, though, when the opportunity presented itself, they threw out another series of kicks. _Shit,_ Undyne thought, _that actually hurt a little._ Not much worse for wear, though, she roared out and surrounded them in a halo of spears. The human rolled and dodged with the grace of a true ballerina. Undyne huffed.

"I'm actually a little impressed," she admitted. They scarfed down what looked like to be a... snowball? The child straightened out, wounds... disappearing. Seemed magic worked pretty well on them. A formidable foe, to say the least. Undyne felt her soul glowing with rage and determination. "But that doesn't mean you'll win." She shot from every possible angle, trying to pin them. Strike after strike, she felt herself failing. No, no, this can't happen. She had to win. She had to win for her friends and for the sake of the entire world. 

In one last attempt, seeing their bloodied and bruised face, she sent out her fastest spears. They struck and pierced through them, eliciting a high-pitched scream. _Finally._ Undyne felt herself relaxing, but she relaxed too soon. The child wrenched the spear out of them and charged at her with it, slamming into her at full force. She got knocked back, the force of the spear making her sputter out a choke. A moment after she landed, she laughed a little. This was it... this was... the end...

"Damn it… so even THAT power… it wasn’t enough…?... Heh… heheheh…. if you… if you think I’m gonna give up hope, you’re wrong..." She grinned her widest, most sincere smile. The child wobbled, obviously very weakened. "’Cause I’ve got my friends behind me," she continued, exerting the last of her effort. Drops of sweat ran down her face. The human looked confused.

"Friends?"

"Alphys told me that she would watch me fight you and if anything went wrong, she would evacuate everyone… by now she’s called Asgore and told him to absorb the 6 human SOULs. And with that power…" She choked again, noticing her lower half... melting. These would be her last words... The child stood weakly over her, and with one last grin, she spat out, "This world will live on…!" 

Her vision blurred, knowing she was fading to dust. _Goodbye, everyone,_ was the final thought that graced her mind before she was one with the howling wind.

**Notes for the Chapter:**

> and that's it for Merciless! I'll be starting the work on Neutralization in a day or two (probably starting tonight lmao because I LOVE BEING STRESSED OUT). Thank you all for reading and I hope you enjoy the rest of my works!
> 
> fun fact: i beat Undyne on the first try but it took me a solid 3 days to beat Sans


End file.
